The subject matter disclosed herein relates to a force compensated probe for measurement of an electrical property of an article.
For electrical generators, the generator armature is provided with electrical insulation to protect the generator components from electrical faults. This insulation performs most efficiently when it is in good condition but tends to degrade when it is moist or when it is exposed to moisture. It is therefore helpful to determine when such moisture is present so that repair can be conducted or planned.
Determining when moisture is present may involve the measurement of the electrical impedance of the insulation. Typically, the insulation has characteristic electrical impedance when it is dry but decreased impedance when moist. As such, one can determine when moisture is present by determining the electrical impedance of the insulation and comparing that impedance with the characteristic impedance for dry insulation. Unfortunately, the tools for measuring electrical impedance are also sensitive to an amount of mechanical force applied by the tools to the insulation being tested so the readings have often been inconsistent.
Efforts to mitigate the problems associated with the sensitivity of tools for measuring electrical impedance have involved the use of audio and/or visual feedback mechanisms referred to as “contact factor” mechanisms in attempts to provide consistent readings. These contact factor mechanisms do not, however, limit an amount of force that can be applied by the operator and are, therefore, subject to operator error.